I am so sorry Rose.
I can certainly feel your pain ~ you expressed it very well. You could print a copy and give it to your T to read, perhaps that would make it easier to get onto this subject. It sounds like you have a lot of intense emotions just below the surface, always in danger of exploding. Talking about these things now could help a lot. Maybe not immediately, but the relief would come much more quickly than if you simply continue to avoid talking about the intense thoughts & feelings.
You have every right to feel like you do. Sometimes, people aren't real considerate of other people's feelings. Some people are often like that ~ just wrapped up in themselves and their world, like you co-worker. And, occasionally other people become wrapped up in the drama & then they snap back into reality again. Either way, it hurts to see others being oblivious and/or carefree to your pain. It's an insult.
Gentle hugs to you....